MMR question

We are due to travel to north Wales on holiday this August. Whilst discussing with the nurse, I was left unclear as to the level of protection my dd will have after the first jab. It was something like she'll have about 88% immunity (so, partial immunity?) or 88% of people develop immunity; the boosters are to 'catch' the 12% who do not develop immunity. If anyone can, I would appreciate some clarity with this.

We're in the Midlands and the nurse told me that there are cases in Shropshire and a few in London. To be honest, I am a bit worried about travelling there, but perhaps I'm worrying too much?

Hi - your son has a 95% chance of being 100% protected with one MMR. The outbreak in Wales is slowing down (see www.wales.nhs.uk/sitesplus/888/page/66389), so hopefully by August, your risk of getting exposed will be small anyway.